Geographic Location
The municipality now known as Castillejos was founded in 1743. It was established by Tagalog Families who migrated from Bataan Province and according to Agustin dela Cavada, in his Histories de Filipinas, Castillejos was recognized as pueblo 26 years ahead of Subic, the coastal town proceeding Castillejos from south.
The municipality of Castillejos is one of the thirteen municipalities that comprise the province of Zambales. It is bounded on the north by municipality of San Marcelino and on the south by municipality of Subic. It has a total land area of 17,744 hectares.
Castillejos is 22 kms. from Olongapo City Proper, 60 kms from Iba and 147 kms northwest of Manila. Travel time is 3 ½ hours from Manila, one hour from Iba and ½ hour from Olongapo City.
Political Subdivision
The Municipality of Castillejos is subdivided into fourteen (14) barangays. Barangay Looc is the farthest barangay with the distance of 7.0 kms from the town proper while Barangay San Juan lies within the heart of the Poblacion. Among the barangays in the municipality, San Pablo and Looc are the largest with 11,037.94 hectares and 2,040.23 hectares respectively. The smallest is Barangay San Roque with a land area of only 22.54 hectares.
Topography and Land Features
Castillejos is situated in a relatively flat terrain especially in the Poblacion area. This slowly becomes hilly as the land proceeds towards the mountainous area. The land feature and the total land area per barangay is as follows:
Barangay Land Feature Land Area
01. Balaybay Plain, Hilly 1,531.97
02. Buenavista Plain 360.24
03. Del Pilar Plain 167.01
04. Looc Plain, Hilly 2,040.23
05. Magsaysay Plain 118.60
06. Nagbayan Plain, Hilly 716.67
07. Nagbunga Plainy -
08. San Agustin Plain 554.40
09. San Jose Plain 194.88
10. San Juan Plain 68.65
11. San Nicolas Plain 217.11
12. San Pablo Plain 11,037.94
13. San Roque Plain 22.54
14. Sta. Maria Plain 29.83
Climate and Rainfall
The climate in Castillejos is characterized by two pronounced seasons: the dry and the wet seasons. The dry season occurs in January to April. However, from the month of May rain starts to fall gradually increasing until August, with typhoons. Rainy season gradually decreases until December.
Soil Characteristics / Classification
Castillejos has four types of soil. The Angeles fine sand which is suitable for lowland rice, vegetables, sugarcane and root crops, is about 60% of the total land area and lies in the Western portion of the town; the Quingua silt loam on the Northern Eastern portion, is around 31%, this is also suitable for lowland and upland rice, vegetable and fruit trees; Antipolo clay is about 10%, lies on the Eastern portion, suitable also for lowland and upland rice and fruit trees; and the mountain soils undifferentiated this compromise the outerrmost or the easternmost part of the municipality, making 10% of its total land area, these are rough soils and mountains are mostly covered with forest, though in some places the land is utilized for upland rice.
Commerce and Trade
The major area for the exchange of goods and services is in the public market, which is located in Poblacion, the site is situated about 20 meters away from the Municipal Hall.
The number of commercial establishments in the municipality is 1,660. These include marketing outlets, lending institutions, restaurants, furniture shop, sari-sari stores and many others. Sari-sari stores with a total number of 477 constitute the predominant form of trading. They provide the day-to-day livelihood of the immediate neighborhood.
At present, the Banco De Oro Unibank Inc. is the only commercial bank in the locality. Zambales Bank, GM Bank and Producers Bank are rural banks. The eight (8) micro-finance business activities are ASA Philippines Foundation Inc., Fundline Finance Corporation, JJB Home Bay Credit Solutions Corporation, M.E Fast Loan Lending Corporation, Pagasa Philippines Lending Company, Inc., ARDCI NGO Group Incorporated, CARD Inc. and Kazama Grameen Inc.
The major industrial activities in the municipality of Castillejos are crushing plant, quarrying and RCP plant. The sites of those activities are characterized by small and medium scale industries build around the urban core and its vicinity. These industrial establishments are classified into rice mills, furniture shop, welding shop, etc.
Raw material and manpower resources are no problem to the sector since they are locally available. The sector has so far been lucky to have the presence of a rural banks and cooperatives which provide financing services
Land and Forest Resources
Hardwood forest species such as narra, calantas, apitong, tanguile and guijo are abundant in the mountainous portion of Castillejos specifically in Sitio Canaynayan, Barangay San Pablo, Barangay Looc and Barangay San Agustin. These forest areas also yield minor products such as bamboo, rattan, jungle vines and cogon.
Tourist Spots, Destinations and Festivals
Main tourist destination in the municipality is the Ramon Magsaysay Ancestral House at Barangay Sta. Maria. Other tourist destinations are Looc Lake and Carmelites Church and Monastery both situated at Barangay Looc.
Another tourist attraction is the “Cenaculo”, an annual commemoration of the Death and Passion of Jesus Christ during Holy Week.
Himno Castillejos
Himno Castillejos

Isang Dakilang Bayang Mahal
Sa atin ay bigay ng Maykapal
Lupa at lahing ikararangal
Noon ngayon magpakaylanman.

Ikaw at ako lahi ay iisa
Sa Castillejos halina
Kayang-kaya kapag sama-sama
Uunlad at giginhawa.

Ang bayan ni Ramon Magsaysay
Itangi at mahaling tunay
Labing-apat Ligang Barangay
Pinag-isa tungo sa tagumpay.

Edukasyon ating linangin
Kalusuga'y pagyamanin
Pagsasaka payabungin
Itanghal sariling atin.

Sa bayan kong minumutya
Mga ngiting nakahahalina
Bukid ilog lawang kay ganda
Sa Castillejos makikita.

Ang bayan kong sinisinta
Ang 'yong ganda'y nagbibigay sigla
Kayang-kaya basta't sama-sama
Ikaw ako tayo magkaisa
Kayang-kaya basta't sama-sama
Ikaw ako tayo magkaisa.

Lyricist: Rogelio I. Besarra
Composer: Maru B. Daria